Safety device for gas mains



N v. 6, 1934. H, B D QE ET AL 9,979,933

SAFETY DEVICE FOR GAS MAINS Filed July 31, 1931 T 2 Sheets-Sheet 1 NOV. 6, 1934. BEDDQES ET AL 1,979,933

SAFETY DEVICE FOR G AS MAINS Filed July 51, 1951 2 Sheets-Sheet 2 Patented Nov. 6, 1934 STATES SAFETY DEVICE FOR GAS MAINS Application July 31, 1931, Serial No. 554,234

12 Claims.

This invention relatest improvements in safety devices for gas mains and its principal purpose is to provide an improved apparatus adapted to prevent the backfiring to a gas main of burning I ,5 gas at the outlet thereof or at any other point where air may enter to form a combustible mixture. The present invention may be used with particular advantage preventing the backfiring of combustible mixtures which may be formed by gases generated in sewage digestion tanks but it may also be employed in any other gas main Where a protective device is esired. The principal object of the invention is to provide a device which will efiectively preventfire or burning gas H from passing through the main toward the source of supply. Another object of the invention is to provide a safety device combining a fire trap with means for collecting the water of condensation in the gas. A further object of the invention is to provide a safety device having oombinedin one unit a fire trap, a collector for the Water of condensation in the gas and a waste gas trap to relieve the excess gas which is not consumed by the burners or other gas consuming devices to which the gas main is connected. A further object of the invention is to provide a fire trap for gas mains comprising a "plurality of spaced parts providing relatively small openings through which the gas must pass and which efiectively prevent the passage of any flame. A further object of the invention is to'provide a fire trap comprising a plurality of superimposed plates which are spaced .apart to permit the gas to pass therethrough and which are preferably provided with means for cleaning the spaces between these plates. Other objects relate to various features of construction and arrangement which will appear more fully hereinafter.

The nature of the invention will be understood from the following specification taken with the accompanying drawings, in which one embodiment is illustrated. 'In the drawings,

Fig. 1 shows a vertical section through one form of apparatus embodying the invention;

Fig. 2 shows a vertical section taken on the line '22 of Fig. 1;

Fig. 3 shows an elevation of the apparatus looking toward the left as viewed in Fig. 2;

Fig. 4is an enlarged horizontal section on the line 44 of Fig. 1, showing the arrangement 01 the spaced plates of the fire trapandthe means for cleaning the spaces between them; and

Fig. 5 is an enlarged vertical sectiontaken on the line 5-5 of Fig.4.

illustrated in the drawings, the invention is shown as comprising a casing 10, which is 1 in the form of an upright cylinder made up of a number of separate sections including a lower cylindrical section 11, and intermediate section 12 and an uppersection 13. The lower section 69 11 rests upon a bottom plate 14 and fits around an annular shoulder 14 which is formed on this plate. At its upper end,,the section .11 of the casing engages an intermediate casting or "fitting 15 and the upper side of this fitting forms a seat for the lower end of the intermediate casing 12. The upper end of the intermediate casing v12 in turn engages another intermediate casing or fitting 16, the upper side of which forms a seat for the upper casing 13. Upon the upper 79 end of the casing 13 there is mounted a top plate 1'7 having an annular shoulder 17 which fits within the inner side of the casing. Suitable packing material 18 is provided between the end of each casing and the fitting or plate which is engaged thereby so that fluid-tight joints are formed when the parts are assembled and clamped together. This clamping action is effected by means of a plurality of vertically extending bolts 20 which pass through the outer projecting portions of the plates 14 and 17 and extend upwardly on the outer sides of the casing sections 11, 12 and 13. Spacing sleeves 21 are mounted on the lower ends of these bolts between their heads and the plate 14 andthe upper threaded ends of the bolts are engaged by nuts 22. When these nuts are tightened, the various casing sections and the intermediate fittings are clamped together and are held tightly between the plate 14 and the plate 17 while the downwardly projecting portionsof the bolts which are held in position by the spacing sleeves 21, serve as legs for holding the entire casing above the floor or other support.

The gas to be consumed flows from the source of supply through a pipe 25 which leads through an opening 17* formed in the top plate 1'7. This pipe may be formed with a separate removable extension 25 which is connected thereto by a threaded coupling 26 and a nut 27 may be provided on the threaded portion of the extension 25 beneath the top plate 1'? for the purpose of clamping the end of the pipe securely in place. with the nut engaging the lower side of the plate and the coupling 26 engaging the upper side thereof. The mouth of the pipe 25 or its extension opens adjacent the bottom of the chamber .28. which is formed within the casing section 16 and the water of condensation in the gas collects in. the bottom of this'chamber as shown at 30. The 1 gas passing from the pipe 25 bubbles through the Water in chamber 28 and enters an upright pipe 31 which is threaded into the central part of the fitting l6 and which communicates with an outwardly directed passage 32 formed therein. A pipe 33 connects the passage 32 with a gas meter which is represented diagrammatically at 34, and after passing through the gas meter the gas flows through a pipe 35 which has a threaded engagement with the fitting 15 to communicate with a passage 36 therein. This passage extends inwardly and communicates with a vertically extending pipe 37 which threadedly engages the central part of the under side of the fitting. The pipe 37 extends downwardly into the chamber 38 which is formed within the lower casing section 11 and the lower end of this pipe has a threaded engagement with a circular head or plate 40. A similar head or plate 41 is spaced downwardly from the head and these members have mounted between thema series of spaced plates 42 in the form of annular rings providing intermediate annular spaces 43 of relatively small dimensions through which the gas passes outwardly. The upper and lower heads 40 and 41, respectively, and the intermediate spaced plates or rings are preferably entirely submerged in a body of water 44 which occupies the lower part of the chamber 38 and the gas which passes outwardly from the region within the annular rings 43 bubbles upwardly through the water 44 and then passes off through a passage 45 which is formed in the fitting 15 to communicate with a pipe 46 1 having connection with the burners or other devices where the combustion of the gas takes place.

The heads 40 and 41 are provided with projecting ears 40 and 41 respectively, and the intermediate annular rings or plates 43 are similarly provided with projecting ears 48" registering with the ears carried by the heads. These registering ears are provided with aligning apertures which 'are engaged by bolts 48 arranged to pass also through apertures formed in the spacing collars 49 vmounted between the rings 43 and also between the heads 40 and 40 and the next adjacent rings. For the purpose of cleaning the spaces 42 between adjacent plates, the lower. head 41 is provided centrally with aloearing 50 x in which is rotatably mounted a vertical shaft 51 50 which is journaled in a bearing 56 carried by the lower plate 14 of the casing. The shaft is adapted to be rotated manually by the operation of a crank handle 57 secured to the lower end thereof and the rotation of this shaft drives the upper shaft 51 through the engagement of a vertical head 58, carried by the crank arm 54, with the side of the crank arm 53. By this arrangement, the shaft 51 may be driven by the shaft 55 without the shafts being in exact alignment since the pin 58 may engage the side of the crank arm 53 at any point within a considerable range. By this cleaning arrangement, the spaces 42 through which the gas must pass may be maintained free of obstructions at all times and these spaces are relatively small, measured vertically, so that fire in the gas line cannot pass back through these spaces into the passage 35-3637 leading from the meter or to any other parts of the gas line located nearer to the source of supply.

The excess of gas which is delivered to the chamber 38 within the lower casing 11, above that which can be consumed by the burners or other gas consuming devices connected to the pipe 41, is allowed to escape through two pipes 60- which threadedly engage the fitting 15, as shown in Fig. 2, and extend upwardly through a body of water 61 which is located in the lower part of the chamber 62 formed within the intermediate casing 12. These pipes 60 are connected at their upper ends to elbows 63 and the other arms of these elbows are connected to down wardly directed pipes 64 which open in the lower part of the chamber 62 beneath the level of the water 61 therein. The excess or waste gas is permitted to pass upwardly through these elbow con nections and then bubbles through the water 61 from the pipe 64 into the chamber 62 from which it escapes as waste gas through a passage 68 in the fitting 16, leading to a waste pipe 69.

The chamber 28 within the upper casing 13 may be filled with sponges or other filtering ma tcrials and access may be had tothis chamber through a cover '70 which is detachably secured to the top plate 17 by nuts '71 engaging the studs 72. In order that an excess of the condensate may not accumulate in this chamber, it is provided with an overflow pipe '73 threadedly engaging a passage 74 in the fitting 16 and extending upwardly therefrom to open at a predetermined level. The passage 74 in the fitting 16 communicates with an elbow 75 which communicates with a pipe 76 located on the outside of the casing and having a U-shaped bend '76 in the lower part thereof. The short arm of this bend communicates with another elbow '77 which leads through the upper part of the lower fitting 15 into the lower part of the chamber 62 of the intermediate casing 12. The overfiow of the condensate from the upper chamber thus supplies the fluid through which the waste gas bubbles away in the intermediate chamber. This intermediate chamber is in turn provided with an overflow outlet 78 which determines the level of the liquid therein and which communicates with an elbow 79 having communication with a downwardly extending pipe 80. This pipe 80 discharges at its lower end through an elbow 81 into the chamber 38 of the lower casing 11, thus supplying the body of liquid 44 in which the plates of the fire trap device are immersed. The level of the liquid 44 in the lower chamber 38 is determined by an overflow connection which is made through an elbow 82 connected to a U- shaped pipe 83 which is thus hung on the outside of the casing, as shown in Fig. 2, with a fitting 84 attached to the upper end thereof for communication with a suitable waste water connection.

A graduated gauge glass 85 is mounted vertically on the side of the upper casing section 13 and is supported at its upper end by a bracket 86 secured to the top plate 17. The lower end of this gauge glass communicates through a manu ally operated valve 8'7 with the lower portion of the chamber 28 and the gas pressure acting on the water 30 forces a portion of this water into the gauge to indicate the degree of gas pressure in this part of the system. Another graduated gauge glass 88 is mounted at the side of the intermediate-casing by meansof manually'operated valves 89 and 90, respectively. These valves may be manipulated to cause this gauge to be used either for indicating the level of the liquid within the chamber of 'the intermediate casing or the pressureofthegas therein. Another graduated gauge glass 91 is mounted at the'side of the lower casing section 11 and is connected to the interior chamber'38 of this casing by upper and lower manually operated valves92 and 93, respectively. This gauge may be employed for indicating the level of the liquid or the pressure of the gas in the lower chamber 38. The valves 89 and 92 connected to the upper ends of the two gauge glasses 88 and 91, respectively, are provided with vent-cocks 94 which may be employed to relieve the pressure in these gauge glasses.

Although one form of the invention has been shown and described by way of illustration, it will be understood that it may be constructed in various other embodiments within the scope of the appended claims.

We claim:

1. The combination with a conduit for combustible gas, of a safety device connected in said conduit and comprising a vessel adapted to contain a liquid a plurality of annular spaced members immersed in a liquid and forming annular restricted passages between them through which the gas is compelled to flow, whereby the passage of a flame through said conduit is prevented.

2. The combination with a conduit for combustible gas, of a casing connected in said conduit, a device mounted in said casing and com- 35 prising a plurality of spaced plates forming restricted passages, said device being connected to said conduit to compel the gas to flow through said restricted passages in passing through said casing, and means operated from the outside of plates carried by said head and spaced apart,

a second head mounted on the undersides of said plates, and a second pipe connected to said casing, whereby combustible gas admitted to said first-named pipe must flow through the passages between said plates in passing through said second-named pipe.

4. The combination of a casing, a pipe leading downwardly into said casing, a head connected to said pipe, a series of annular plates carried by said head and spaced apart, a second head mounted on the undersides of said plates, a second pipe connected to said casing, whereby combustible gas admitted to said first-named pipe must flow through the passages between said plates in passing through said second-niamed pipe, and rotary means operated from the outside of said casing for cleaning the spaces between said plates.

5. The combination in a safety device for gas mains, of a casing, of a pipe leading downwardly ries of arms extending outwardly from said shaft and engaging the spaces between said rings, and means operated from the outside of said casing for rotating said shaft.

6. The combination in a safety device for gas mains, of a casing, a pipe leading downwardly into crankarms each secured on one of said shafts, a

transverse pin carried by one of said crank arms and bearing against the other of said crank arms, and means operated from the outside of said casing for rotating said second-named shaft.

'7. The combination in a safety device for combustible gas mains, of a casing adapted to be connected in the gas main and having a plurality of chambers, means located in one of said chambers for collecting the condensate in said gas, means for conducting the overflow of said condensate from said chamber to another of said chambers, and means comprising a plurality of spaced members located in said last-named chamher for preventing the passage of a flame through said casing and said gas main.

8. The combination in a safety device for combustible gas mains, of a casing adapted to be connected in the gas main and having a plurality of chambers, means located in one of said chambersfor collecting the condensate in said gas, means for conducting the overflow of said condensate from said chamber to another of said chambers, means comprising a plurality of spaced members located in said lastnamed chamber for preventing the passage of a flame through said casing and said gas main, and means for maintaining a predetermined level of said condensate in said last-named chamber.

9. The combination in a safety device for combustible gas mains, of a casing adapted to be connected in the gas main, said casing comprising a plurality of chambers, means mounted in one of said chambers for collecting the condensate in said gas, means located in another of said chambers for preventing the passage of a flame through said casing and said gas main, means for connecting said last-named chamber with gas-consuming devices, means for conveying the excess gas from said last-named chamber to another of said chambers, and means forming a liquid trap in said last-named chamber for controlling the waste of said excess gas.

10. The combination in a safety device for combustible gas mains, of a casing adapted to be connected in the gas main and comprising a plurality of superimposed chambers, means for admitting combustible gas from the source of supply to the uppermost chamber, means for collecting the liquid condensate in the gas in said uppermost chamber, means for conveying the gas from said uppermost chamber through a gas meter to the lowermost chamber, means located in said last-named chamber for preventing the passage of a flame through said casing and said meter, means for connecting said last-named chamber to gas-consuming devices, and means for conveying the excess gas not consumed by said devices from said last-named chamber to said intermediate chamber.

11. The combination in a safety device for combustible gas mains, of a casing adapted to be connected in the gas main and comprising a plurality of en erirnposed chambers, means for admitting combustible gas from the source of supply to the uppermost chamber, means for collecting the liquid condensate in the gas in said uppermost chamber, means for conveying the gas from said uppermost chamber through a gas meter to the lowermost chamber, means located in said last-named chamber for preventing the passage of a flame through said casing and said meter, means for connecting said last-named chamber to gas-consuming devices, means for conveying the exess gas not consumed by said devices from said last-named chamber to said intermediate chamber, and means for maintaining a predetermined level of said liquid condensate in said uppermost chamber and conveying the overflow thereof to said intermediate chamber for maintaining a liquid trap in said intermediate chamber through which said excess gas flows. 

